1. Field of the Invention
This invention relates to hold-downs for securing components to circuit assemblies and more particularly to lanced hold-downs for securing connectors to printed circuit boards.
2. Description of Related Art
Various apparatus exist for locating and securing connectors onto printed circuit boards (PCBs) prior to and during soldering of terminals mounted in the connector to the circuit assembly.
Terminal pins of through-mount connectors have been aligned or crimped to secure connectors onto PCBs. See, for instance, U.S. Pat. Nos. 4,907,978 and 4,847,588. However, these hold-downs do not work well for softer or more flexible terminals. Further, the non-parallel alignment of pin tails as disclosed in U.S. Pat. No. 4,907,978 requires the pin tails to be bent into a straightened position in order to insert the pin tails into standard parallel rows of holes.
Terminal pins of through-mount connectors have been configured to secure the connector to a PCB by causing an interference fit between press-fit sections of the terminals within plated-through holes in a PCB. For instance, U.S. Pat. No. 4,735,587 discloses a header with two rows of pins with selected opposed pin pairs having cantilever retention arms for engaging interior surfaces of circuit board holes to hold the header to a circuit board prior to and during soldering. The pins are held in the board holes merely by the interference fit between linear corners or edges of the pins against the wall of the board holes. The particular shape and orientation of the retention arms results in the need for a relatively high insertion force in order to press the pin into a hole.
Other hold-downs that are separate from the connector terminals have been disclosed or used for securing either surface-mount connectors or through-mount connectors to PCBs. Rivets or nut and bolt assemblies have been used for this purpose. Other such apparatus are disclosed, for instance, in U.S. Pat. No. 4,717,219. These hold-down apparatus take up a relatively large surface area of the connector and PCB. Further, these hold-downs typically require a secondary operation after the hold-down is inserted in a board hole to spread the hold-down out to retain the hold-down in the hole. Other generally flat hold-downs are disclosed that take up less surface space on a PCB. See, for instance, U.S. Pat. No. 4,907,987. However, the retention force caused by the interference fit between this hold-down in a connector housing is low which may necessitate the use of a special seating tool to connect such a hold-down to a board.
Solder tail portions of through-mount terminals have been cut or lanced forming a finger angled with respect to the flat sides of the solder tails. The finger comprises a compliant section for forming an interference fit in a plated-through hole in a PCB. However, softer metal solder tails having a similarly formed angled finger buckle when forced into or towards a similarly sized plated-through hole.
It is an object of this invention to provide a hold-down that can be used to hold down a connector on a printed circuit board at least while terminals mounted in the connector are soldered to the circuit board.
It is an object of this invention to provide the hold-down such that it can be used to hold down either a through-mount connector or a surface mount connector onto a printed circuit board.
It is an object of this invention to provide the hold-down such that it can be part of one of the terminals or contact elements mounted in the housing or apart from the connector terminals.
These and other objects of the invention will be clear from the following description.